This invention relates generally to air decontamination and more specifically, it relates to a method of and a device for separating paint residuals and solvent particles contained in a stream of the exhaust air discharged from paint spray chambers or similar treatment stations, especially from those that are used for painting metal parts such as car bodies and the like.
The term "paint" is here used to designate materials such as lacquer, varnish or other painting materials having similar properties and that can be removed from an exhaust gas in similar manner as a lacquer. The solvent can be contained in the paint or it can be additional added in the course of the method of this invention to dissolve the paint residuals. The method of this invention is also suitable for removing other contaminating substances suspended in the exhaust air even if such additional substances are not mentioned explicitly.
In painting shops, the paint residuals and solvents deposited from the paint mist are conventionally washed out by means of wet precipitators or separators. Nonetheless, the degree of separation depends among others on the pressure difference in the separating system, on the pollution of the separating water and on the effectiveness of used coagulation chemicals. Conventional prior-art devices and methods have a relatively limited effect and therefore are unsatisfactory. Solvents contained in the exhaust air are not separated at all and are freely discharged in the outer atmosphere and cause considerable pollution. Economically feasible methods for purifying the exhaust air from paint spray chambers so as to remove both the paint residuals and the paint dissolving particles suspended in the air, have not yet been devised.